JPH11242821A - Optical pickup actuator for cd and dvd - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical pickup actuator for CD and DVD which is reduced in the mass and height of a lens holder, tolerant of disturbance, and made compact. SOLUTION: An objective 525 for DVD and an objective for CD are installed within the radius of the lens holder 500 without projecting from the top surface of the lens holder. A slide shaft 565 which projects from the center of the bottom surface of a cylindrical yoke 560 in parallel to the optical paths of the objectives is coupled with the axial hole 530 of the lens holder 500. On the inner peripheral surface of the yoke 560, a pair of 2nd magnets 570 which control the tracking of the objective and a couple of 2nd magnets 580 which control the focusing of the objectives are installed. The couples of 1st and 2nd magnets are arranged alternately at 90 deg. intervals. The lens holder 500 has winding coils 540 fitted on the circumferential surface, i.e., at the positions corresponding to the couples of 1st and 2nd magnets. At the center part of each winding coil, a magnetic body is installed. The height and radius of the lens holder 500 are reduced and the mass of the lens holder becomes small, so that the parasitic resonance of the lens holder is positioned in a high frequency range.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical pickup actuator, and more particularly, to a height and a radius of a lens holder by recessing a CD objective lens and a DVD objective lens within the radius of the lens holder. The present invention relates to an optical pickup actuator in which the resonance frequency of the lens holder is increased by reducing the resonance frequency.

[0002]

2. Description of the Related Art In recent years, data reproduction / reproduction using an optical disc such as a laser disc or a compact disc has been advanced.
Recording systems have been developed. There is provided an optical pickup device that irradiates a laser beam along a data recording track on the disk to reproduce or record information from the optical disk, and reproduces data based on a beam reflected on the track. When the tracks are spirally formed on the optical disk, the sectors in a single track are not the same distance from the center of rotation of the disk due to the eccentricity in the disk. Therefore, in order to accurately irradiate the track with the laser beam in the reading mode, tracking control is essential. Further, since the disk is rotating in the reading mode, the distance from the optical pickup device to the disk fluctuates minutely. Such fluctuations make accurate data reading difficult, so focusing control is essential. For the above-mentioned focusing control, a focusing error is detected from the laser beam reflected by the optical disk. The focusing control operation is performed by moving the objective lens according to the detected focusing error signal. For this purpose, a focusing actuator having a coil appropriately configured to move the objective lens in the optical axis direction of the objective lens is operated.

On the other hand, a CD-ROM, which is a reproduction optical disk related to multimedia information, is a medium having a diameter of 12 cm, a thickness of 1.2 mm, and a track pitch of 1.6 μm, and records 540 megabytes of information on one side. be able to. Recently, MPEG (Moving Picture Experts G
roup), using image compression data technology.
A digital video disk (DVD) in which video information is recorded on a ROM has been developed.

In order to reproduce data from a disk having a high recording density, the spot diameter of a laser beam must be adjusted. For this purpose, the wavelength of the laser of the optical pickup device must be short (for example, about 63
5 nm), the numerical aperture (NA) of the objective lens must be large (eg, about 0.6). However, the aberration due to the tilt of the disk is directly proportional to the cube of the numerical aperture of the objective lens and increases in direct proportion to the thickness of the disk. Therefore, if the numerical aperture of the objective lens is too large, it causes a decrease in the tilt margin of the disk. If the numerical aperture of the objective lens is the same, SD having a thickness of about 0.6 mm
(Standard density) The specified DVD is, for example, about 1.2 mm.
Has a tilt margin twice that of a typical CD having a thickness of

[0005] Despite the limitations described above, C having the standard density and a thickness of about 1.2 mm
There is a need for an optical pickup device capable of reproducing information from both D and a DVD having a thickness of about 0.6 mm at a high density. Hereinafter, a conventional optical pickup actuator for both CD and DVD will be described with reference to FIGS.

FIG. 1 is an exploded perspective view showing an example of a conventional axially slidable optical pickup actuator for both CD and DVD. FIG. 2 is a longitudinal sectional view taken along the line II-II of FIG. 3 is the conventional CD and DVD shown in FIG.
FIG. 9 is a perspective view showing an integrated magnet provided in the dual-purpose axially-slidable optical pickup actuator. FIG. 4 is an exploded perspective view showing another example of the conventional axially slidable optical pickup actuator for both CD and DVD.

As shown in FIGS. 1 to 3, a conventional CD
An axially slidable optical pickup actuator for dual use with a DVD includes a cylindrical lens holder 110, lens coupling portions 113 and 115, a winding coil 120, a cylindrical yoke 130, a shaft 135, a pair of first magnets 140, and a pair of first magnets 140. It is composed of the second magnet 150. The shaft 135 projects vertically upward from the bottom surface of the yoke 130. The pair of first magnets 140 are composed of a plurality of magnets disposed on the inner peripheral surface of the yoke 130 so as to form a flat angle with each other. The magnets forming the pair of second magnets 150 are disposed on the inner peripheral surface of the yoke 130 so as to be perpendicular to the magnets forming the pair of first magnets 140. The magnets forming the pair of second magnets 150 are disposed so as to form a flat angle with each other.

The lens holder 110 is provided on its outer peripheral surface, that is, the pair of first and second magnets 14.
It has a plurality of winding coils 120 mounted at positions corresponding to 0 and 150, respectively. The above-mentioned lens connecting part 1
Reference numerals 13 and 115 protrude from the upper surface of the lens holder 110 and protrude in the radial direction of the lens holder 110. An objective lens 112 for CD and an objective lens 114 for DVD are installed in the lens coupling portions 113 and 115, respectively. The guide groove 1 is provided below the lens coupling portions 113 and 115, that is, on the circumferential surface of the lens holder 110, in parallel with the optical axis direction of the objective lenses 112 and 114.
17 are provided. The guide groove 117 is formed in the bottom surface of the yoke 130 and selectively coincides with the through hole 119 through which the laser beam passes. The above lens holder 1
10 has a shaft hole 118 that is coupled to the shaft 135.
The lens holder 110 is lifted from the bottom surface of the yoke 130 by a force acting between the magnetic body 116 and the pair of the first and second magnets 140 and 150. The magnetic body 116 is provided at the center of the winding coil 120 mounted on the outer peripheral surface of the lens holder 110.

The lens connecting portions 113 and 115 are provided in the radial direction of the lens holder 110 and the objective lens 11.
2, 114 are installed in a state protruding in the optical axis direction. Therefore, since the mass of the lens holder 110 is large, its resonance frequency is low. If the resonance frequency is low,
The actuator is disadvantageous in that it is vulnerable to disturbances due to the influence of parasitic resonance.

The objective lenses 112 and 114 selectively coincide with the optical axis when the lens holder 110 rotates. The pair of first and second magnets 140 and 150 are provided to assist the rotation of the lens holder 110 without obstructing the rotation of the lens coupling portions 113 and 115. The height of the yoke 130 is higher than the combined height of the height L1 of the pair of second magnets 150 and the height H1 from the second magnet 150 to the lens coupling portion 115. The yoke 130
Is higher than the sum of L1 and H1 in order to protect the lens holder 110 and the objective lens 114. Therefore, since the bulk of the optical pickup actuator becomes large, the actuator cannot be made compact.

The height of the yoke 130 is closely related to the method of forming the second magnet 150 shown in FIG. Although only the second magnet 150 is shown in FIG.
The method for forming the first magnet 140 is the same. That is, the magnet M1 is of an integral type, and is obtained by magnetizing N and S poles on neodymium iron (NdFe).
A non-magnetized area m is formed between the magnetized N and S poles of the magnet M1. The non-magnetized area m cannot form a magnetic field. Therefore, unless the height of the magnet M1 is increased by the height of the non-magnetized area,
A magnetic field required to rotate the lens holder 110 cannot be obtained. As a result, the height of the yoke 130 increases, and the radius of the yoke 130 increases, making it difficult to achieve a compact actuator.

FIG. 4 shows another embodiment of a conventional axially slidable optical pickup actuator. The actuator has a cylinder 210 to which a focusing coil FA and a pair of tracking coils TRa and TRb are mounted. A rectangular lens holder 220 is formed above the cylinder 210. The above lens holder 22
A plurality of lens connecting portions for mounting the DVD objective lens La and the CD objective lens Lb are protruded vertically upward on one side of the reference numeral 0. The lens connecting part includes a first lens connecting part 222 and a second lens connecting part 224. On the lens holder 220, a balance member 226 for leveling the lens holder 220 is installed at a position facing the lens coupling portions 222 and 224. A shaft hole 228 is formed at the center of gravity of the lens holder 220 so as to coincide with the center of the cylinder 210. The cylinder 210 is connected to the yoke 230 by fitting the shaft hole 228 and a shaft 232 projecting from the center of the yoke 230 in parallel with the optical axis direction. A projection 234 projecting from the yoke 230 in parallel with the optical axis direction is connected between the shaft 232 and the cylinder 210. On the inner peripheral surface of the yoke 230 facing the outer peripheral surface of the cylinder 210, a pair of magnets 236 that perform electromagnetic action with the focusing coil FA and the pair of tracking coils TRa and TRb are provided.

In the optical pickup actuator shown in FIG. 4, the lens holder 220 rotates above the yoke 230 to rotate the lens coupling portions 222 and 224.
Is formed so as to protrude from the lens holder 220. Therefore, the height of the actuator is increased, which makes it difficult to make the actuator compact.

The lens holder 220 has the balance member 226. Therefore, as the mass of the lens holder increases, the resonance frequency of the lens holder decreases, and the optical pickup actuator is affected by the parasitic resonance.

[0015]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide:
An object of the present invention is to provide an optical pickup actuator that is resistant to external disturbances by reducing the mass of a lens holder to position parasitic resonance in a high-frequency region. Another object of the present invention is to provide a compact optical pickup actuator by reducing the height of a lens holder.

[0016]

According to the present invention, there is provided an axially slidable optical pickup actuator for both CD and DVD, which has an axis projecting vertically upward from a bottom surface and an inner peripheral surface. 4 installed at 90 ° intervals
An optical pickup actuator comprising: a yoke having two magnets; a cylindrical lens holder rotatably and vertically movable coupled to the shaft and having a coil wound on an outer peripheral surface at a position facing the magnet. The lens holder has a laser hole penetrated in a direction parallel to the optical axis direction of the objective lens within a radius of the lens holder, and a CD and DVD objective lens is provided above the laser hole. Are formed.

Here, the magnet is a two-piece magnet.
The magnet is composed of a parallel magnet in which electrodes are arranged in a direction parallel to the optical axis direction, and a orthogonal magnet in which electrodes are arranged in a direction orthogonal to the optical axis direction,
The parallel magnets and the orthogonal magnets are installed alternately. At the center of the winding coil, a magnetic body for floating the lens holder is attached.

According to the optical pickup actuator of the present invention, the lens holder is floated by the magnet on the inner peripheral surface of the yoke and the magnetic material on the outer peripheral surface of the lens holder. The tracking and focusing servos are performed in the vertical direction (focusing direction) and the horizontal direction (tracking direction) of the lens holder according to the direction and strength of the force acting between the magnet and the winding coil.
Performed by exercise to.

Since the objective lens is set within the radius of the lens holder, the size and mass of the lens holder can be reduced. As the mass of the lens holder decreases, the resonance frequency of the lens holder increases, and the parasitic resonance moves to a high-frequency region accordingly. If the parasitic resonance moves to the high frequency region, the sensitivity of the optical pickup actuator is improved. At the same time, an optical pickup actuator having a simple configuration and an easy manufacturing process can be obtained.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an optical pickup actuator according to the present invention will be described in more detail with reference to the accompanying drawings. FIG. 5 is an exploded perspective view showing an axially slidable optical pickup actuator for both CD and DVD according to the present invention, FIG. 6 is a longitudinal sectional view taken along the line III-III of FIG. 5, and FIG. FIG. 8 is a perspective view showing a combined state of an axially slidable optical pickup actuator for both CD and DVD according to the present invention, and FIG. 8 shows an example of a two-piece magnet installed in the axially slidable optical pickup actuator for both CD and DVD according to the present invention. FIG. 9 is a longitudinal sectional view showing the use state of an axially slidable optical pickup actuator for both CD and DVD according to the present invention, and FIG. 10 is a conventional optical pickup actuator and an optical pickup according to the present invention. FIG. 3 is a diagram illustrating a tracking range of an objective lens in an actuator.

The cylindrical yoke 560 has a sliding shaft 565 projecting vertically upward from the center of the bottom surface. A through hole 567 penetrating the bottom surface of the yoke 560 is formed in a part of the bottom surface. A pair of first magnets 570 and a pair of second magnets 580 are mounted inside the circumferential surface of the cylindrical yoke 560. The pair of first magnets 570 is composed of two magnets arranged to form a flat angle. The polarity of each magnet of the pair of first magnets 570 is arranged in a direction orthogonal to the sliding shaft 565. The pair of second magnets 580 includes two magnets arranged at a flat angle. The polarity of each magnet of the pair of second magnets 580 is arranged in a direction parallel to the sliding shaft 565.
The magnets of the pair of first magnets 570 and the magnets of the pair of second magnets 580 are alternately arranged at 90 ° intervals. First and second of the pair
The magnets 570 and 580 are mounted at the same height as the cylindrical yoke 560. The yoke 560
A through hole 567 through which the laser beam from the hologram element 700 passes is formed on the bottom surface of the hologram element 700. A full mirror 750 is provided below the through-hole 567 to make the path of the laser beam incident from the hologram element 700 coincide with the optical axes of the objective lenses 515 and 525.

The above magnet is manufactured in a two-piece form. That is, the integral magnet is divided into two so as to maintain the polarity arrangement of the integral magnet in which the N pole and the S pole are magnetized. The two-piece magnet abuts the N-pole of the first magnet piece M2 and the S-pole of the second magnet piece M3 divided into two as described above, and the S-pole of the first magnet piece M2 and the second magnet piece. It is formed by abutting the N pole of M3. When the two-piece magnet thus formed is attached to the inner peripheral surface of the yoke 560, the two-piece magnet is attached so that the magnetic field of the magnet to be used does not include a non-magnetized area. For example, as shown in FIG. 8, the polarity arrangement of the second magnet 580 is such that the magnetic field acting in parallel to the direction of the sliding shaft 565 is formed by the N pole of the first magnet piece M2 and the second pole. The portion where the S pole of the magnet piece M3 abuts is the sliding shaft 5
The two-piece magnet is arranged so as to be arranged in a direction parallel to 65.

The lens holder 500 has a cylindrical shape. The lens holder 500 has a shaft hole 530 at a position corresponding to the sliding shaft 565 of the cylindrical yoke 560. Within the radius of the lens holder 500, two laser holes 5 having the same distance to the center of the lens holder 5
35 are formed. The laser holes 535 are separated by a predetermined angle. A first lens coupling part 510 and a second lens coupling part 520 are formed above the laser hole 535, respectively. First lens coupling unit 510
Is provided with an objective lens 515 for DVD, and the second
An objective lens 525 for a CD is installed in the lens coupling unit 520. The first and second lens coupling parts 510 and 52
0 serves as a rib for increasing the rigidity of the lens holder 500.

On the outer peripheral surface of the lens holder 500, four winding coils 540 are mounted. A first coil is mounted on the outer peripheral surface of the lens holder 500 corresponding to the acute angle formed by the objective lens. A second winding coil is mounted on the outer peripheral surface of the lens holder 500 at a position which is at a flat angle with the first winding coil. Between the first winding coil and the second winding coil on the outer peripheral surface of the lens holder 500, a third winding coil and a fourth winding coil disposed so as to form a flat angle with each other are attached. Can be The first winding coil and the third winding coil are arranged at an interval of 90 °, and the second winding coil and the fourth winding coil are also arranged at an interval of 90 ° from each other. On the lower surface of the lens holder 500, there are formed a number of balance portions 505 that are recessed upward. The balance portion 505 is formed such that the center of the shaft hole 530 becomes the center of gravity of the lens holder 500.

At the center of each of the winding coils 540 on the outer peripheral surface of the lens holder 500, a magnetic material 55
0 is set. The first magnetic body provided at the center of the first coil is deflected toward the DVD objective lens 515. The second magnetic body installed at the center of the second winding coil is the DVD objective lens 51.
5 is deflected. The third magnetic body provided at the center of the third coil is the objective lens 52 for the CD.
5 and is deflected in a direction away from 5. The fourth magnetic body provided at the center of the fourth coil is deflected in a direction away from the DVD objective lens 515.

The radius of the yoke 560 is equal to the radius of the sliding shaft 56.
It is larger than the inner radius from 5 to the pair of magnets 570, 580. The lens holder 500 is installed inside the yoke 560 by fitting the sliding shaft 565 of the yoke 560 into the shaft hole 530. that time,
Any one of the laser holes 535 is the same as the through hole 5
67, and the respective winding coils face the respective magnets.

Next, the operation of the optical pickup actuator according to the present invention will be described. First, the through hole 5
It is assumed that the optical axis of the CD objective lens 525 matches the optical axis of the CD objective lens 525. The lens holder 500 includes the magnetic material 55
The yoke 560 floats from the bottom surface of the yoke 560 by a magnetic field between the pair of magnets 570 and 580. The traveling path of the laser beam emitted from the hologram element 700 is changed by the full mirror 750. Therefore, the laser beam passes through the through hole 567 from below and travels along the optical axis of the objective lens 525 for CD. The advanced laser beam is applied to the upper disk 6
After being focused on the recording pit No. 00, it is reflected. The reflected laser beam is applied to the objective lens 525 for the CD.
After passing through the through hole 567 again, the light enters the photodetector (not shown) in the hologram element 700 via the full mirror 750. The focusing and tracking states at the data recording pits are detected from the laser beam thus incident.

When a focusing servo is required, a focusing servo current is applied from a servo system (not shown) to the winding coil facing the second magnet 580 of the pair. When a focusing servo current is applied to the winding coil, the pair of second magnets 580
A force acts in a direction parallel to the sliding shaft 565 by the magnetic flux. Accordingly, the lens holder 500 on which the CD objective lens 525 is installed receives a force in the direction of the sliding shaft 565 to execute focusing servo.

When a tracking servo is required, a servo system (not shown) supplies the first magnet 5 of the pair.
A tracking servo current is applied to the winding coil facing 70. When a tracking servo current is applied to the winding coil, a force acts in the rotation direction of the lens holder 500 due to the magnetic flux of the pair of first magnets 570. Accordingly, the lens holder 500 including the CD objective lens 525 receives a force in the horizontal direction to execute tracking servo.

On the other hand, when the positions of the objective lens 525 for CD and the objective lens 515 for DVD are to be changed, the first pair of the pair used for the tracking servo is used.
A large amount of current is instantaneously applied to the winding coil disposed to face the magnet 570. When a large amount of current instantaneously flows through the winding coil, the lens holder 5
00 largely rotates in the magnetic flux direction of the pair of first magnets 570. Since the magnetic body 550 is deflected in one direction, the rotation of the lens holder 500 is assisted.

FIG. 10 shows the tracking servo distance of the objective lens on the conventional optical pickup actuator and the optical pickup actuator according to the present invention. In the figure, reference numeral 114 denotes a conventional DVD objective lens, and reference numeral 515 denotes a DVD objective lens according to the present invention. The tracking servo angle centered on the sliding shaft 565 is the same as that of the prior art and the present invention, but the tracking movement distance is D1 and D2, which are different from each other. That is, the tracking movement distance D1 of the conventional DVD objective lens 114 is larger than the tracking movement distance D2 of the DVD objective lens 515 according to the present invention.
The difference between the tracking movement distances is caused by the fact that the distance from the sliding shaft 565 to the center of each of the objective lenses 515 and 525 is smaller than that in the related art.

As described above, when the distance from the axis to the objective lens becomes short, the tracking drive sensitivity decreases. The drive sensitivity is proportional to the value of (B × L × N) / (KL × R). Here, B is the strength of the magnetic field, L is the length of the coil, and N indicates the number of turns of the coil. KL is a rigidity value determined by the attraction between the magnet and the magnetic material,
R indicates the resistance of the coil. That is, the rigidity value (KL) is reduced in order to compensate for a decrease in drive sensitivity. However, as the rigidity value (KL) decreases, the resonance frequency of the lens holder decreases. In order for the optical pickup actuator for both DVD and CD to normally perform the reproduction mode, the decrease in the resonance frequency must be compensated. The DVD and CD optical pickup actuators must satisfy both DVD and CD servo bands. CD servo band is 1.1KH
z, and the servo band of the DVD is 2.4 KHz.
In general, for stable operation of the optical pickup actuator, it is necessary to design so that a parasitic resonance frequency does not exist in a stable band which is 10 times as large as a servo band.
Therefore, the optical pickup actuator for both DVD and CD of the present invention has a stable band of 11 KHz for CD and D
It must be designed to simultaneously satisfy 24 KHz, which is the stable band of VD. That is, the parasitic resonance frequency band must be located in a higher frequency band than the stable band. As described above, in order to shift the parasitic resonance frequency to a frequency band higher than the stable band, the parasitic resonance frequency must be raised above 24 KHz. The parasitic resonance frequency (fn) is proportional to (KH) / m. Here, KH is the rigidity value of the lens holder, and m indicates the mass of the lens holder. That is, in order to increase the parasitic resonance frequency (fn) from a required value (24 KHz), it is necessary to reduce the mass of the lens holder or increase the rigidity of the lens holder. Generally, since the mass and the stiffness value are in a proportional relationship, it is difficult to increase the parasitic resonance frequency. In order to solve such a problem, the optical pickup actuator of the present invention employs a configuration as shown in FIG. 5 in order to increase the rigidity value (KH) without increasing the mass (m) of the lens holder. The lens holder which has was adopted. The accompanying decrease in tracking drive sensitivity was compensated for by reducing the strength (B) of the magnetic field of the magnet.

[0033]

As described above, according to the optical pickup actuator of the present invention, the lens holder provided with the objective lens floats by the magnet on the yoke, the magnetic material of the lens holder, and the sliding shaft. It is kept in the state. Tracking and focusing servos are performed by moving the lens holder in the vertical direction (focusing direction) and in the horizontal direction (tracking direction) by the amount of current supplied to the winding coil and the magnetic flux of the magnet. The switching of the positions of the CD objective lens and the DVD objective lens installed in the lens holder is performed by adjusting the amount of the tracking servo current. Therefore, an optical pickup actuator having a simple configuration and an easy manufacturing process can be obtained.

When a two-piece magnet is used, the height of the lens holder of the present invention is reduced by the height of the non-magnetized area from the height of the lens holder of the conventional optical pickup actuator. Therefore, the optical pickup actuator can be made compact and the mass of the lens holder can be reduced, so that the parasitic resonance can be moved to the high frequency range. If the parasitic resonance moves to the high frequency region, a stable optical pickup actuator operation can be obtained.

Further, two pairs of magnets having different polar arrangement directions are fixed to the yoke, and coils wound in the same shape are arranged at positions corresponding to the respective magnets. Therefore, in using the objective lens for CD and the objective lens for DVD, tracking and focusing servo are performed along the magnetic flux direction of the fixed magnet.

Although the present invention has been described in detail with reference to preferred embodiments, the present invention is not limited to these embodiments, and it is needless to say that modifications and improvements can be made without departing from the spirit of the present invention. is there.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing an example of a conventional axially slidable optical pickup actuator for both CD and DVD.

FIG. 2 is a longitudinal sectional view taken along the line II-II of FIG.

FIG. 3 is a perspective view showing an integral magnet installed in the conventional axially slidable optical pickup actuator shown in FIG. 1;

FIG. 4 is an exploded perspective view showing another example of a conventional axially sliding optical pickup actuator.

FIG. 5 is an exploded perspective view showing an axially slidable optical pickup actuator for both CD and DVD according to the present invention.

FIG. 6 is a vertical sectional view taken along the line III-III in FIG. 5;

FIG. 7 is a perspective view showing a combined state of an axially slidable optical pickup actuator for both CD and DVD according to the present invention.

FIG. 8 is a perspective view showing an example of a two-piece magnet installed in an axially slidable optical pickup actuator for both CD and DVD according to the present invention.

FIG. 9 is a longitudinal sectional view showing a use state of an axially slidable optical pickup actuator for both CD and DVD according to the present invention.

FIG. 10 is a diagram showing a tracking range of an objective lens in a conventional optical pickup actuator and an optical pickup actuator according to the present invention.

[Explanation of symbols]

 500 Lens holder 505 Balancing part 510 First lens coupling part 515 Objective lens for DVD 520 Second lens coupling part 525 Objective lens for CD 530 Shaft hole 540 Winding coil 550 Magnetic body 560 Cylindrical yoke 565 Sliding shaft 567 Penetration Hole 570 Pair of first magnets 580 Pair of second magnets 700 Hologram element

Claims (3)

[Claims] An axis projecting vertically upward from a bottom surface,
A yoke having four magnets installed at 90 ° intervals on an inner peripheral surface; a yoke having four magnets coupled to the shaft so as to rotate and move up and down, and a coil wound on an outer peripheral surface at a position facing the magnet. An optical pickup actuator comprising: a cylindrical lens holder installed; wherein the lens holder has a laser hole penetrating in a direction parallel to the optical axis direction of the objective lens within a radius of the lens holder; An optical pickup actuator for both CD and DVD, wherein a plurality of lens coupling portions for mounting an objective lens for CD and DVD are formed above the optical pickup actuator. 2. The optical pickup actuator according to claim 1, wherein the magnet has a two-part shape. 3. The magnet comprises: a parallel magnet having electrodes arranged in a direction parallel to the optical axis direction; and a orthogonal magnet having electrodes arranged in a direction perpendicular to the optical axis direction. 3. The optical pickup actuator according to claim 1, wherein the parallel magnets and the orthogonal magnets are alternately provided.